Studies on the Concentrations of Cd, Pb, Hg and Cr in Dog Serum in Korea

Heavy metal pollution has become a serious health concern in recent years. Dogs are a very good indicator of the pollution load on the environment. They share people's environment and are exposed to the action of the same pollutants. This study estimated the heavy metal contents in the serum of dogs in domestic districts, and assessed the age, sex, feeding habits, living area, breeding environment and smoking habit of the owners. The findings suggest that dogs can be used to monitor the environmental quality of heavy metals. The mean concentrations of heavy metals in the dog serum from 204 samples (108 male and 96 female) were 0.22${\pm}$0.01 $\mu$g/ml, 0.24${\pm}$0.04 $\mu$g/ml, 0.61${\pm}$0.08 $\mu$g/ml, and 0.50${\pm}$0.06 $\mu$g/ml (for Cd, Hg, Pb, and Cr), respectively. Concentrations of Pb, Cd, Hg, and Cr in the dog serum were higher in Yeongnam including Ulsan, and Seoul higher than those of Chungchong and Honam, especially Pb concentration, which was significantly higher (p<0.01). Concentrations of Cd, Hg, Pb, and Cr in serum, were increased by age (p<0.05). When commercial pet food was provided to dogs, Cd and Cr concentrations were significantly higher in dog serum than dogs fed a human diet (p<0.01 in Cd and p<0.05 in Cr). Heavy metal concentrations of dogs owned by smoking owners, were higher than non-smoking owners although there was no significant difference.